Stitch cam arrangement for knitting machines



Dec. 10, 1957 H. s. BURDETT 2,

s'm'cn CAM ARRANGEMENT FOR mrr'rmc MACHINES Filed llay 7, 1956 I s Sheets-Sheet 1 'Dec. 10,- 1957 H. BURDETT STITCH CAM ARRANGEMENT FOR KNITTING MACHINES Filed ne 7, 1956 5 Sheets-Sheet 2 STITCH CAM ARRANGEMENT FOR KNITTING MACHINES Filad lay 7.1956

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s. BURDETT' 2,815,651

3 Sheets-Sheet 3 United States Patent STITCH CAM ARRANGEMENT FOR KNITTING MACHINES Henry Sidney Burdett, Knighton, England, assignor to G. Stihbe & Co. Limited, Leicester,-England, a'Brltish company Application May 7, 1956, Serial No. 583,210

11 Claims. (Cl. 6654) This invention concerns circular knitting machines for the production of articles of knitted footwear such as stockings, three-quarter hose, half hose and socks.

Machines of this kind are adapted to knit withrotary motion, as well as with rotary-reciprocatory motion for the knitting of heel and toe pouches, and the cam box associated with the cylinder, or the appropriate cylinder, as the case may be, is furnished at the feeder, or the main feeder, with two stitch cams, viz. a legging (or forward) stitch cam and a heeling (or reverse) stitch cam.

Thus, as is well known to those acquainted with the art, during the production of a heel ora toe pouch the loops in the courses knitted in the forward direction are drawn by virtue of the appropriate needles being retracted, by the legging cam, whilst the loops in the intervening courses knitted-in the reverse direction are similarly drawn as the result of retraction of the needles by the heeling cam.

Now it can sometimes happen, during the knitting of a heel or a toe, that the loops knitted in the alternate courses are of a different length to the knitted loops in the'intervening courses. This is a fault commonly known as slur-galling and one which results in uneven quality.

Since, heretofore, the legging and h'eeling stitch cams in a circular knitting machine of the kind referred to have invariably been mounted upon a common'slide, the undesirable condition resulting in slur-galling could only be overcome by grinding a little'oif the appropriate one of these two cams.

The object of the present invention is to provide an improved arrangement of the legging and heeling cams enabling the foregoing faulty condition to be expeditiously remedied without recourse togrinding.

It is, however, an aim that the stitch cams in the improved arrangement shall be simultaneously adjustable for the purpose of varying the quality of the loops, as will be hereinafter described. A

According to this invention, the legging and 'heeling cams in a circular knitting machine of the kind herein referred to are mounted upon separate movable carriers which are individually adjustable suchwise as to enable any discrepancy between the effective length of one cam as compared with that of the other to be readily removed.

Preferably, the improved arrangement includes means whereby the separate movable carriers, when once accurately set to draw loops of thesame length, can be'simultaneously adjusted to the same extent in either sense to vary the loop length (quality). p

In a convenient embodiment of the invention each of the separate movable stitch cam carriers is in the form of a slide mounted for adjustment up or down with at least a portion thereof in and guided by an independent slot formed in the cam box, or the appropriate cam box of the machine, as the'case may be. 7 V

Advantageously, manually operable screw means may be provided for elfecting individual adjustment of the saidseparateslides.

2,815,651 Patented Dec. 10, 1957 For adjusting the pre-set slides both together and so varying the quality of the loops, according to knitting requirements, the said slides may be connected with individually mounted members adapted to be actuated simultaneously from a common component movable automatically under suitable control.

In order that the invention may be more clearly understood and readily carried into practical effect, a specific constructional example thereof will now be described with reference to the accompanying drawings, wherein,

Figure l is a general perspective view of so much of a circular knitting machine of the superimposed needle cylinder type as is necessary to show the outer'parts of the separate movable carriers for the legging and heeling stitch cams, the manually operable screw means for effecting individual adjustment of the separate carriers, and the controlled connections for eifecting simultaneous adjustment of the latter,

Figure 2 is a detail plan view of fragmentary portions of the bottom cylinder and the associated cam box and shows, in addition to the leggingand heeling stitch cams themselves, some of the connections depicted in Figure 1,

Figure 3 is a cross-sectional view taken on the line 111-411 of Figure 2, and

Figure 4 is a side view, partly in section, depicting the individually movable member with which one of the separate cam carriers is connected, and showing also the manner in which this member is actuated from the control component.

Like parts are designated by similar reference characters throughout the drawings.

In each of Figures 1 and 2, the rotary bottom or plain needle cylinder of a circular hose or half hose knitting machine of the superimposed needle cylinder type is indicated at 1. This cylinder normally rotates but for knitting heel and toe pouches, oscillates, within a stationary bottom cam box 2. At a knitting location, the cam box 2 is furnished with a legging (or forward) stitch cam 3 and a heeling (or reverse) stitch cam'4, these two cams, shown in plain in Figure 2, being suitably spaced apart circumferentially with a fixed centre cam -5 disposed between them. The two stitch cams 3 and'4 are of conventional form, and each has associated with it a guard earn 6 (Figure 3) between which and said cam is a space constituting a cam track 7 to-receive the knitting butts 8 of bottom needle-actuating sliders such as that indicated at 9. The reference numeral 10 indicates one of the double-ended latch needles with which the machine is equipped.

Each of the two companion stitch cams 3 and 4 is'secured, by screws such as that depicted at '11 in Figure 3, to the inner part 12 of a composite slide S of'mainly rectangular form. Also secured by screws '13 to the same part 12, immediately beneath the stitch cam, is the corresponding guard cam 6. As will be seen from Figure 3, each of the separate composite slides S comprises, in addition to the inner part 12, an outer part 14 of an intermediate tenon 15, all three being securely attached to one another by screw bolts 16. Each slide S is mounted for movement up and down vertically, with its intermediate part or tenon 15 located and guided within a rectangular slot or opening 17 formed in the stationary cam box 2. The back of the inner 'slide part. 12, moreover, is let into and'is s'lidable up and down within a vertical recess formed in the inner face of the cam box 2, whereas the back of the'outer'slide'part 14- is movable up and down in contact with a fiat formed on the outer surface of the said box (see Figure 3"). The upper ends of the inner and purer parts 12 and 1 1 of each stitch cam slides are bridged by aplateJlS whichis secured in position by screws 19. Located in' 'a hole 20 formed in the "to'pof the cam box 2, immediately beneath each bridge plate 18, is a compression spring 21 the opposite ends of which bear on the bottom of the hole and the underside of the said plate respectively. The springs are, therefore, arranged to subject the slides S and hence also the stitch cams 3 and 4 carried thereby to upwardly directed spring pressure.

The outer part 14 of each cam slide is formed with an outwardly directed lug 22 which is drilled with a vertical hole 23 through which is inserted a screw 24. The head 24a of this depending screw 24, which is formed with a screw-driver slot, is shaped at its underside to fit and rest in a part-spherical counter-bore 23a formed in the upper surface of the lug 22. As illustrated in Figure l, the leading, i. e. lower, end of the said screw is screwed into a tapped hole formed axially in the upper end portion of a vertically disposed link member 25. A lock nut 26 provided on each screw 24 is normally screwed down into contact with the upper end of the link member 25. As shown more clearly in Figure 4, the lower extremity of each link member 25 is articulated to the outer end of a horizontally disposed arm 27a of a small bellcrank 27 which is mounted to fulcrum about a pivot pin 28 set in a housing 29 rigidly attached, by screws 30, to the bed plate 31 of the machine. The other arm 27b of the bell crank extends downwardly and is adapted to be permanently maintained, by the spring 21 controlling the relevant cam slide S, in contact with one end of a loose, horizontally disposed pin 32 mounted for sliding movement within an open-ended hole formed in the corresponding housing 29. The opposite end of the loose pin 32 is arranged to be acted upon by a small block 33 which is attached, by screws 34, to a control ring 35. This ring is accommodated in an annular recess cut in the bed plate 31 and is adapted to be automatically turned either clockwise or anti-clockwise to varying extents from the main control drum 36 of the machine, through intermediate connections presently to be described.

Each of the two housings 29 is in the form of a solid block which has formed therein a right-angular slot 29a to accommodate the arms 27a and 27b of the corresponding bell crank 27.

To the control ring 35 which is, of course, common to both stitch cam slides S, is attached a triangular plate 37 whereby the said ring is actuated. The outer end of the plate 37 is connected, by means of a link 38, with one arm 39a of a two-armed lever 39 which is fulcrumed at 40 for turning movement in a horizontal plane. The other arm 3% of the lever 39 is in turn connected, by an adjustable connecting rod 41, with an upwardly extending arm 42a of a cam lever 42 mounted to turn in a vertical plane. The said cam lever is fulcrumed at 43 on a bracket 44 secured to the periphery of the bed 31, and has a toe (not shown) arranged to be acted upon by cams such as 45 attached to the control drum 36.

Thus, if the knocking-over point of either of the two stitch (legging and heeling) cams 3 and 4 is found to be at a height different to that of the other cam, thereby causing slur-galling, the fault can be readily corrected by eifecting an individual adjustment of either of the two cams to bring the respective knocking-over points into the same horizontal line. Such an adjustment, in the particular example described with reference to the drawings, is made by first slackening the relevant locknut 26, then turning the corresponding screw 24 to the required extent in the appropriate direction, and finally setting the adjustment by retightening the lock nut. An upward adjustment of either of the two stitch cams is, of course, made under the action of the associated compression spring 21, whereas a downward adjustment is made against the spring action.

Automatic adjustments of the two cams 3 and 4 together are made by turning the common control ring 35 either clockwise, in which case the pressure exerted by the aforementioned pins 32 upon the depending arms 27b of the bell cranks 27 is relieved thereby permitting simultaneous upward movement of the cams under the spring action, or anti-clockwise so that these pins are caused to press on the bell cranks and so pull down the cams 3 and 4 together against the said action.

I claim:

1. In a circular knitting machine of the kind herein referred to, in combination, a needle cylinder which is arranged to rotate, as well as to have imparted thereto rotary-reciprocatory motion for the knitting of heel and toe pouches, an annular cam box surrounding said cylinder and having formed therein two circumferentially spaced and independent upright slots, legging and heeling stitch cams provided in said cam box for forward and reverse knitting respectively, separate slides by which said two stitch cams are carried, portions of said slides being mounted for movement up and down within the independent slots, means for adjusting said slides individually in the slots suchwise as to enable any discrepancy between the effective length of one stitch cam as compared with that of the other to be removed, and means whereby said separate slides can be simultaneously adjusted to the same extent, for the purpose herein described.

2. A combination according to claim 1, wherein the slides are controlled by springs against and under the action of which the slides move when adjusted.

3. A combination according to claim 1, wherein manually operable screw means are provided for effecting individual adjustment of the said separate slides.

4. In a circular knitting machine of the kind herein referred to, in combination, a needle cylinder which is arranged to rotate, as well as to have imparted thereto rotary-reciprocatory motion for the knitting of heel and toe pouches, an annular cam box surrounding said cylinder, and having formed therein two circumferentially spaced and independent upright slots, legging and heeling stitch cams provided in said cam box for forward and reverse knitting respectively, separate slides by which said two stitch cams are carried, portions of said slides being mounted for movement up and down within the independent slots, means for adjusting said slides individually in the slots suchwise as to enable any discrepancy between the eifective length of one stitch cam as compared with that of the other to be removed, individually mounted movable members whereby the separate slides can be adjusted together to the same extent for the purpose described, link members connecting said slides with the individually mounted members, and an automatically movable common control component from which said individually mounted members are simultaneously actuated.

5. In a circular knitting machine of the kind referred to, in combination, a needle cylinder which is arranged to rotate, as well as to have imparted thereto rotaryreciprocatory motion for the knitting of heel and toe pouches, an annular cam box surrounding said cylinder, and having formed therein two circumferentially spaced and independent upright slots, legging and heeling stitch cams provided in said cam box for forward and reverse knitting respectively, separate slides by which said two stitch cams are carried, said slides being mounted for movement up and down within the independent slots, and each such slide being formed with a lug having therein a hole, compression springs acting on the slides to subject the latter and the stitch cams carried thereby to an upwardly directed spring pressure, a screw inserted downwardly through the hole in each lug with the head of the screw resting upon the lug, link members having therein tapped holes into which the leading ends of said screws are screwed, these screws being rotatable to effect individual adjustment of the slides in the slots against or under the action of the springs suchwise as to enable any discrepancy between the effective length of one stitch cam as compared with that of the other to be removed, individually mounted movable members to which the link members are articulated and whereby the separate slides can be adjusted together to the same extent for the pur pose described, and an automatically movable common control component from which said individually mounted members are simultaneously actuated.

6. A combination according to claim 5, wherein a lock nut provided on each screw is normally screwed down into contact with the appropriate end of the corresponding link member.

7. A combination according to claim 5, wherein the said individually mounted members consist of bell cranks.

8. In a circular knitting machine of the kind herein referred to, in combination, a movable cylinder which is arranged to rotate, as well as to have imparted thereto rotary-reciprocatory motion for the knitting of heel and toe pouches, an annular cam box surrounding said cylinder, and having formed therein two circumferentially spaced and independent upright slots, legging and heeling stitch cams provided in said cam box for forward and reverse knitting respectively, separate slides by which said two stitch cams are carried, portions of said slides being mounted for movement up and down within the independent slots, and each slide being formed with a lug having therein a hole, compression springs acting on the slides to subject the latter and the stitch cams carried thereby to an upwardly directed spring pressure, a screw inserted downwardly through the hole in each lug with the head of the screw resting upon the lug, link members having therein tapped holes into which the leading ends of said screws are screwed, these screws being rotatable to effect individual adjustment of the slides in the slots against or under the action of the springs suchwise as to enable any discrepancy between the effective length of one stitch cam as compared with that of the other to be removed, bell cranks to which the link members are articulated and whereby the separate slides can be adjusted together to the same extent for the purpose described, housings within which the bell cranks are pivotally mounted, a fixed bed to which said housings are rigidly attached, an automatically movable common control component from which the bell cranks are simultaneously actuated, parts which are attached to said component, and movable elements in the housings interposed between said parts and the arms of the bell cranks remote from the link members, these arms being maintained perma nently in contact with the movable elements by the springs controlling the stitch cam slides.

9. A combination according to claim 8, wherein the parts attached to the common control component consist of small blocks.

10. A combination according to claim 8, wherein the bell crank housings are rigidly attached to a bed plate of the machine, and the common control component consists of a ring which is accommodated in an annular recess formed in the said bed and is adapted to be automatically turned either clockwise or anti-clockwise to varying extents from a main control unit through intermediate connections.

11. In a circular knitting machine of the kind herein referred to, in combination, a needle cylinder which is arranged to rotate, as well as to have imparted thereto rotary-reciprocatory motion for the knitting of heel and toe pouches, an annular cam box surrounding said cylinder and having formed therein two circumferentially spaced and independent upright slots, legging and heeling stitch cams provided in said cam box for forward and reverse knitting respectively, separate slides by which said two stitch cams are carried, portions of said slides being mounted for movement up and down within the independent slots and means for adjusting said slides individually in the slots suchwise as to enable any discrepancy between the efiective length of one stitch cam as compared with that of the other to be removed.

References Cited in the file of this patent UNITED STATES PATENTS 

